CANT SING FOR BROADWAY! =[?

okay...im not that confident in my voice but i am very much in love with musical theatre...like u have no idea how much i am in love! i dont think my voice is broadway-like and i am also an alto...i just want some advice on how i can better my voice and what typez of roles on broadway i shud go after...the types of roles i like are onez that are comical and i love to dance!